The One Thing You Should Know About Prepping Potatoes Ahead of Time

Whether you’re planning a Thanksgiving menu or hosting a special dinner, finding ways to cut down on prep work can be game-changing, especially if you’re feeding a large crowd. Peeling potatoes ahead of time sounds like a clever hack for making mashed potatoes or French fries—that is, if you’re doing it correctly.

Here's the problem: when you slice into a potato, you expose its natural phenols to oxygen, a chemical reaction that results in an almost immediate pinkish hue. They’re still safe to eat, and it doesn’t change the taste, but who wants to serve mauve potatoes?

Eating healthy should still be delicious.

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The best way to keep prepped potatoes from turning brown is to submerge them in cold water. When peeling potatoes ahead of time, follow these pointers to ensure the best results.

Don't soak cut potatoes longer than overnight.

If keeping potatoes in water for more than an hour, refrigerate. However, don't soak them any longer than overnight—after that, the potatoes start to lose their structure and flavor.

Do soak small cuts of potatoes only for a short time.

Photo: Caitlin Bensel

Small cuts, like diced potatoes, get waterlogged faster, so are best kept in cold water for a short time, like while you prep other ingredients.

Bigger cuts, on the other hand, can hang out happily in water for 8-12 hours. One of the best ways to use this trick is when making mashed potatoes—you don’t have to cut them small and you’ll be adding liquid anyway. In the morning, put peeled, quartered potatoes in a pot of cold water and refrigerate; when it’s time for dinner, just put the pot on the stovetop and fire it up!

Don't soak shredded potatoes.

Victor Protasio

Such a fine cut takes on water quickly and is typically cooked until golden—think latkes or potato pancakes—so none of that discoloration will show anyway. Instead, give shredded potatoes a good rinse to remove their starch (so that they crisp up better during cooking), pay them dry, then cook according to your recipe.

Do cut some types of potatoes right before cooking.

If your dish depends on the most crisp exterior (like pommes Anna) or requires your potatoes to give off very little moisture (like a gratin with other water-heavy veggies), there's no need to cut those ahead of time and soak them. For these types of tubers, your best bet is to cut them right before use.